Image processing apparatus, image processing system, and program therefor

A control apparatus connected to a light projector for projecting pattern light having a coordinate component in at least one direction that is determinable and a camera imaging an object upon which the pattern light is projected to acquire a pattern image, the control apparatus comprising a processor configured with a program for calculating three-dimensional coordinates of at least one point on the object based on the pattern light and the pattern image;

• wherein the processor is configured with the program to perform operations comprising:
• operation as a determination unit configured to determine a first point on the pattern image;
• operation as a calculation unit configured to calculate a second point in a projection plane of the pattern light based on a location of the first point on the pattern image, the second point corresponding to the first point;
• operation as a correction unit configured to calculate a third point based on the second point in the projection plane, a nonlinear line in the projection plane calculated by analyzing the pattern image, and an epipolar line in the projection plane calculated based on the first point;
• and
• operation as a calculation unit configured to calculate the three-dimensional coordinates of the point on the object based on the first point and the third point.

A method performed by a control apparatus connected to a light projection apparatus for projecting pattern light having a coordinate component in at least one direction that is determinable and an imaging apparatus for imaging an object upon which the pattern light is projected to acquire a pattern image, the method calculating three-dimensional coordinates of at least one point on the object based on the pattern light and the pattern image, the method comprising:

• determining a first point on the pattern image;
• calculating a second point in a projection plane of the pattern light based on a location of the first point in the pattern image, the second point corresponding to the first point;
• calculating a third point based on the second point in the projection plane, a nonlinear line in the projection plane calculated by analyzing the pattern image, and an epipolar line in the projection plane calculated based on the first point;
• and
• calculating the three-dimensional coordinates of the point on the object based on the first point and the third point.

A non-transitory computer-readable recording medium storing a program for use in a control apparatus comprising a processor connected to a light projection apparatus for projecting pattern light having a coordinate component in at least one direction that is determinable and an imaging apparatus for imaging an object to which the pattern light is projected to acquire a pattern image, the program, when read and executed, causing the processor to perform operations comprising:

• determining a first point on the pattern image;
• calculating a second point in a projection plane of the pattern light based on a pattern imaged on a location of the first point, the second point corresponding to the first point;
• calculating a third point based on the second point in the projection plane, a nonlinear line in the projection plane calculated by analyzing the pattern image, and an epipolar line in the projection plane calculated based on the first point;
• and
• calculating the three-dimensional coordinates of the point on the object based on the first point and the third point.